Cleaning the arsenic(V) contaminated water for safe-guarding the public health using novel composite material

Abstract

With increasing arsenic contamination scenes reported around the globe, the highly promising materials are important to remove the arsenic from industrial and specified contaminated for safe-guarding the public health. In this study, we have prepared ligand anchoring inorganic-organic frameworks based well-ordered, high surface area composite materials for selective arsenic(V) (As(V)) removal from contaminated water. Adsorption studies were evaluated in batch mode with the function of pH, time, initial As(V) concentration, counter-ions and reuses by suitable eluent. Before starting the As(V) adsorption, the composite materials were protonated using 2.0 M HCl. The materials exhibited high adsorption efficiency in low pH area, however; the neutral pH region (7.0) was selected to avoid the divalent anions effect as the monovalent arsenate species were dominated. In the neutral pH region, the basicity of divalent HAsO42− was much greater than the divalent SO42− and the divalent HAsO42− was easily made the strong hydrogen bonding with the protonated composite materials surface. Then the effects of monovalent and divalent anions were not affected in the selective As(V) adsorption by the composite materials. In addition, the other cations did not affect the As(V) adsorption as the data clarified. The composite material was highly matched to the Langmuir model with the monolayer coverage. In addition, the determined maximum adsorption capacity was 142.25 mg/g. The As(V) was eluted from the composite materials with 2.0 M HCl, and the regenerated to the original pattern. The regenerated materials were exhibited the same functionality and used successively in several adsorption-elution-reuses cycles. Therefore, the newly fabricated composite material is an interesting, efficient and economical sustainable composite material and could be used selective As(V) removal from real contaminated water.